Prism-binocular.



J. HEGKEL.

PRISM BINOGULAR. APPLIOATIQN IILED JAN. 16, 190B.

Patented May 31, 1910.

UNITED STATES PATENT OFFICE.

JAKOB HECKEL, F JENA, GERMANY, ASSIGN'OR TO THE FIRM 0F CARL ZEISS, OF JENA, GERMANY.

PRISM-BINOCULAR.

To all whom it may concern: 4

Be it known that I, J AKOB I'IEGKEL, mechanician, a citizen of the German Empire, and residingat Carl-Zeiss strasse, Jena, in the. Grand Duchy of Saxe-Weimar, Ger- .many, have invented new and useful Prism- Binoculars, of which the following is a specification.

The invention consists in a new prism binocular of that kind, in which the single telescopes are connected together by a hinge for the purpose of adapting the-distance between the oculars to the inter-pupill ary distance of the observer. This instrument is provided with means for being adjusted so that its two optical axes are parallel to one another and remain so notwithstanding alteration of the distance between the oculars.

As may be easily understood, the adjustment will fuIfiIthe latter condition, if the optical axis of either single-telescope be directed parallel to the axis'of the hinge. This has itherto been attained by having the position ofthe single telescope suitably altered relatively to the hinge, a method which is, however, of limited applicability, because it is based upon a detachable connection existing between the casing of the single telescope and its hinge? arms.

The adjusting means according to the present invention may be applied to prism binoculars of everykind, because it does not affect the position of the single telescope casing with regard to the hinge and also does not otherwise materially restrict free-v dom in the build of the binocular. This ad justing means is connected with one of. the two component lens systems, either the objective or the genial, in' such a way that the place of the c mponent lens system may be varied in the plane perpendicular to'the' Fig. 2 is a section on the Specification of Letters Patent. Patented May 31, 1910,

Application filed January 16, 1908. Serial No. 411,106.

required for the purpose of rendering this axis parallel to that of the hinge- The direction of the optical axis is givenin all telescopes the. magnification of which deviates from unity-by the direction of entrancexof that pencil of arallel rays the final deflection of which t rough the telescope is zero, that is to say, which also leaves the instrument inthedirection of entrance.

Rays fromapoint which lies on the axis of the hinge at a very great distance away enter either single telescope parallel to the axis of the hinge. If these rays also emerge parallel to the said axis, the optical axis of either single telescope has the required direction. In every other case at least one optical axis is to be rotated correspondingly. The amount of shifting to be undertaken for this purpose with the ocular or the obj ective in the plane perpendicular to the hinge axis is .found to be the product of two factors, one of which is the sum of the focal distances both of the objective and the ocular and the other is the tangent of the angle of inclination of the optica axis to the axis of the hinge. r

In order to conveniently adjust the ocular tube or the objective by shifting it, while the rotation of the optical axis produced thereby is being observed, and hereafter fasten it on the casing of the single telescope,

.the mount of the objective or the ..ocular may have, as shown in Fig. 1 with respect to the latter, a flange a with holes for screws 6, .these holes being comparatively, wide so as to allow transverse shifting of they tube when the screws are loosened.

Other well known means may be employed 5 for the same adjustment, 'for example as shown in Figs. 2 and 2 screws 0 working crosswise in two directions, or as shown in Figs. 3 and 3 a double eccentric consisting a lensmount d with an outer' eccentric surface and a rin e rotatably fitted in the objective casing and alsowith an inner eccentric surface-on the lens mount (1, an annular nut e beingprovided for fastening the double eccentric as adjusted.

I claim:

1. In a hinged prism binocular the combination, in each of the single telescopes, with the prism system and the"tw6*-=com onent lens systems, of means for adjustmgone of the comonent lens systems in a plane perpendicu ar to the axis of the hinge.

2. In a hinged prism binocular 't he combination, in each of the single telescopes, with the prism system and the two comonent lens systems, of a double' eccentric or adjusting one of the component lens systems in'a plane perpendicular to the axis of the bin e. j

3. In a inged prism binocular the combination, in each of the single telescopes, with the prism casing, of an ocular connected with the prism casing, an objective casing fastened to the prism casing, an objective lens mounted in an eccentric ring, another eccentric ring rotatably fitted 0n the eccentric lens mount and also in the objective casing, and means for fixing the objective parts as adjusted.

J AKOB HEOKEL.

Witnesses PAUL KRfiGER, FRITZ SANDER. 

